Loud speaker



L. D. HARRIS LOUD SPEAKER April 17, 1928.

Filed June 12. 1926 2 Shee't s-Sheet 1 v gwuentoa': L. ZZHarn's,

April 17, 1928. 1,666,854 L. D. HARRIS LOUD SPEAKER Filed June 12. 1926' 2 Sheets-Sheet 2 gwuemfoz Patented Apr. 17, 1928.

UNITED STATES.

LELANDD. HARRIS, OF SALT LAKE CITY, UTAH.

LOUD SPEAKER.

Application filed June 12,

This invention relates to sound reproducing devices of that type known as loud speakers, and has for one of its objects to improve and sim lify the general construc- 6 tion of devices this character and to provide one that will be exceedingly sensitive to weak electrical currents and will emi-t soft, natural and mellow tones.

With the foregoing and other objects in 1 view, the nature of which will become apparent as the description proceeds, the invention consists of the construction, combination and arrangement of arts hereinafter fully described and cla med, and illustrated in 'the accompanying drawings,

wherein:

Figure 1 is a bottom plan view of a sound reproducing device constructed in accordance with my invention,

Figure 2 is a sectional view taken on the vertical planes indicated by the lines 22 of Figure 1,

Figure 3 is a detail view of the electromagnet of the device, I

Figure 4 is a sectional view taken on the plane indicated by the line 44 of Figure 3,

Figure 5 is a sectional view taken on the plane indicated by the line 5-5 of Figure 4,

Figure 6 is a sectional view taken on the plane indicated by the line 6 6 of Figure 4,

Figure 7 is a detail perspective view of the pole pieces ,of the permanent magnets of the device,

Figure 8 is a detail perspective View of the armature and armature supporting frame of the electromagnet, and

Figure 9 is a detail perspective view of V the core of the spool of the electromagnet.

Corresponding and like parts are referred to in the following description, and designated in the several views of the accompanying drawings, by similar reference characters.

.In the drawings, ldesignates the case of the sound reproducing device. This part consists of a body member 2 and a cap memher 3 which are connected together by screws 4. The cap member 3 is provided with a hollow stud 5 which projects centrally therefrom and is externally screw threaded to permit a born, not shown, to be connected thereto. Theinner wall or throat 6 of the stud 5 tapers inwardly. A diaphragm 7 is secured to and between'the case members 2 and 3 and is'maintained out of direct contact therewith by a rubber gasket 8. The

1926. Serial 1T0. 115,523.

diaphragm 7 is circular and is provided with corrugations 9 which are arranged concentrically with respect to each other and to the center of the diaphragm and which gradually increase in size from the center toward the edge of the dia hragm.

Semi-circular an permanent magnets 10 and 11 are secured to the 'case member 2 by screws 12. The magnets 10 and 11 are arranged with their like poles in opposed relation, and secured by the screws 12 to the ends of the-magnets are pole pieces 13 and 14. The pole piece 13 is secured to the magnets 10 and 11 at one side thereof, and the pole piece 14 is secured to the magnets at the opposite side thereof. The pole pieces 13 and 14'extend inwardly from the magnets 10 and 11 and gradually decrease in width in the direction of their inner ends. The outer ends of the pole pieces 13 and 14 are provided with air gaps 15, and the inner ends 16 of these parts are of U-form and.

the outer faces of the sides 20, retain these parts and the coil 18 in assembled relation. A frame 22 is removabl positioned in the core 19, and is provide with shoulders 23 which contact with the core 19' to limit the extent of its insertion into the core. An armature 24 is rockably supported within the frame 22 by a spindle 25, and is provided with an apertured extension orlug 26 whichfits in a corresponding extension 27 of the frame 22. A link 28 connects the armature 24 to the diaphragm 7, andthis part is secured to the lug 26 and to the center of the diaphragm. The pole piece ends 16 contact with the frame 22 and with the sides of the spool, and as the result hold the electromagnet 17 against casual movement. The frame 22 is of greater thickness than the armature 24 in order .to permit the free movement of the latter. The pole piece ends 16 are positioned to one side of the center of the device so as to permit the link 28 to be arranged in the axis of the diaphragm 7. The terminals 18 of the coil 18 are secured to binding posts 29 carried by a terminal block 30 which is secured by screws 31 to the end 16 of the pole piece 13.

This device may be connected to the electrical lreproducer for phonograph records forming the sub'ect-matter of my copending application, dled the 12th day of June, 1926, and serially numbered 115,524 This connection may be establishedby leads extending from the reproducer to the binding give exact proportions. Furthermore, the

said drawings are illustrativeof a preferred construction, it being my expectation that various changes and modifications may be made without departing from the spirit and scope of my invention.

What is claimed is 1. A sound reproducing device comprising a diaphragm, arcuate permanent magnets, pole pieces arranged diametrically of the magnets and having their outer ends secured to the opposite sides of the magnets the inner ends of the pole pieces being oi substantially U-form and arranged in oposed relation within the magnets, a coil ocated within the inner ends of the pole pieces, a frame extending through and beyond the coil and engaged by the inner ends of the pole pieces to secure it and the coil in lace, an armature arranged within and roc ably supported by the frame, and an element connecting the armature to the diaphragm.

.2. A sound reproducer comprising a diaphragm, a permanent magnet, pole pieces connected at their outer ends to the ma et and having inner ends of substantially U- form, a coil located within the inner ends of the pole pieces, an open frame extending through and beyond the coil and engaged at points beyond the coil by the inner ends of the pole pieces to secure it and the coil in place, an armature arranged Within and rockably supported by the frame, and an element connecting the armature to the diaphragm.

3. A sound reproducing device comprising a diaphragm, a permanent magnet, pole pieces connected to the magnet, a coil associated with the magnet, sides for the coil, a hollow core passing through the coil and sides and provided with lugs contacting with the outer faces of the sides, an armature rockably supported within the coil, and an element connecting the armature to the diaphragm.

In testimony whereof I afiix my signature.

LELAND HARRIS. 

